For me it's like this:

1. the Time of Angels
2. the Doctor's Wife
3. the Sontaran Stratagem
4. Daleks in Manhattan
5. Aliens of London
6. the Girl in the Fireplace

it's really unlikely for me to dislike a s2 episode, but I really hate this one :S all because of Reinette.

Season 5 for me is not my favorite at all. So I vote for The Time Of Angels. But really close is The Girl In The Fireplace juste because of Reinette.

That's a though one. Episodes 4 are great.

THitF. I hate reinette so much.
The doctor loves Rose, right? And then boom, here comes some blonde queen and now I love her oh-so-much UGH CAN'T STAND IT.